Making New XSSFWorkbook Extremely Slow On .NET 5+

[Only-FPS]

Hello, I just have a question during change my .NET Framework project to .NET 7

So I made a test to compare the speed between .net framework and .net 5+ with 21 small size of .XLSX files(~100 rows).
Here is my test code.

static void Main(string[] args)
{
	string[] FileList = Directory.GetFiles(@"C:\Excel", "*.xlsx");
	iPrevTickCount=Environment.TickCount;
	Console.WriteLine(string.Format("Start. Elapsed Time -- {0}s", TimeSpan.FromMilliseconds(Environment.TickCount-iPrevTickCount).TotalSeconds.ToString()));
	foreach(string File in FileList)
	{
		XSSFWorkbook workbook = new XSSFWorkbook(File);
	}
	Console.WriteLine(string.Format("done. Elapsed Time -- {0}s", TimeSpan.FromMilliseconds(Environment.TickCount-iPrevTickCount).TotalSeconds.ToString()));
	Console.ReadKey();
}

As a result, .NET 7 takes about 1.6 seconds that is slower than .NET Framework which takes about 0.3 seconds

This Phenomenon maintains even I Iterate the whole code, .NET Framwork takes 0.09s, while .NET 7 is taking 1s.

Has this always been like this on .NET 5+?

[tonyqus]

Can you send me the Excel files? I'd like to reproduce the test?

Btw, which .NET framework are you using?